An amplitude normalization circuit may be used for a power supply with a PFC (Power Factor Correction) function in the related art.
In conventional amplitude normalization circuits, in order to generate a “waveform” having a constant amplitude, an input waveform is digitized by an A/D converter, amplitude-normalized by a digital arithmetic circuit, and then converted back into analog form by a D/A converter.
On this account, the circuit size of conventional amplitude normalization circuits is increased due to the D/A converter, the A/D converter and the complicated digital arithmetic circuit. In addition, since the generated waveform depends on the resolutions of the D/A converter and the A/D converter, there is a limitation in the reproducibility of the “waveform”.